add filter zeros tool

phase2/src/bin/filter_zeros.rs

@@ -0,0 +1,21 @@
+extern crate phase2;
+extern crate exitcode;
+
+use std::fs::File;
+use phase2::circom_circuit::{load_params_file, filter_params};
+
+fn main() {
+    let args: Vec<String> = std::env::args().collect();
+    if args.len() != 3 {
+        println!("Usage: \n<in_params.params> <out_params.params>");
+        std::process::exit(exitcode::USAGE);
+    }
+    let in_params = &args[1];
+    let out_params = &args[2];
+    println!("Exporting {}...", in_params);
+    let mut params = load_params_file(in_params);
+    filter_params(&mut params);
+    let mut writer = File::create(out_params).unwrap();
+    params.write(&mut writer).unwrap();
+    println!("Created {}.", out_params);
+}